12v -24v connection to arduino input

Discussion in 'General Electronics Chat' started by jonfarrugia, Mar 8, 2016.

  1. jonfarrugia

    Thread Starter Member

    Feb 19, 2010
    I am building a circuit that would connect inputs between 12 to 24vdc to an arduino mega. I would normally accomplish this using a resister and zener diode. However, using a resister and zener diode will draw too much current because I have about 30 inputs. Each zener needs about 50ma of current draw to keep it in the 5v area. 30 x 50ma 1.5amps. Therefore, I need a circuit that would provide 5v to an arduino input from a 12 to 24 supply with very minimal current draw. Any ideas?
  2. tcmtech

    Well-Known Member

    Nov 4, 2013
    Standard off the shelf automotive power port to USB adapter. Most are rated for 12 - 24 VDC input and can supply around 2 amps on the better ones.

    Might cost you up to $8 for a high quality one though. :p